By Ken Tucker
Updated March 26, 1999 at 05:00 AM EST

Singer-guitarists Jack Black and Kyle Gass are Tenacious D, a tubby twosome who perform intensely personal songs about how great Tenacious D is. This scruffily magnificent parody of singer-songwriter egotism had a cameo in the 1996 movie Bio-Dome and began invading TV last season, with a couple of short films following Mr. Show With Bob and David (Show‘s Bob Odenkirk and David Cross are executive producers of D). Now back in half-hour installments, Jack and Kyle are stalked by a fan (they think he’s a psycho, yet they’re so pleased by his dedication, they end up scaring him); get a ”road gig” that turns nightmarish when they run out of windshield-wiper fluid and have to stop at a cult compound that’s about to be attacked by the government; and conduct a ”power rehearsal” in their apartment that gets them in trouble with a new neighbor. If the joke is that these guys are deluded hacks, what makes the joke work is that Black (Mars Attacks!) and Gass (The Cable Guy) commit to their material with the demented vigor of true artistes, and they also write and perform really terrific ”bad” songs (sample lyric: ”Climb upon my faithful steed/Then we’re gonna smoke some weed…”). Music clubs all over the country will consider shutting down open-mike nights once they get a load of Tenacious D, but you’ll probably want to join their fan club. A-